In the first instance, Monsignor Charles Journet explains, a dogma is a particular formulation of a truth of which the reality is a mystery and therefore incommunicable. The prophetic and immutable statement which the dogma, or the article of faith, represents has its source in revelation, and is proclaimed to all people as a manifestation of God's will to enlighten and thus save all mankind. Once it has been revealed by God through the human medium it cannot disappear for itdoes not depend upon human assent for its existence or ratification. Its proclamation through revelation is the first stage. The second aspect is the sanctifying acceptance of the dogma through the inspiration of faith, a personal gift from God which can be consciously or uaconsciously accepted or rejected, and is then active or inactive according to the co-operation of the individual. These two aspects of dogma, the manner of its manifestation and the manner of its recognition and acceptance, are examined by Mgr Journet as he considers historically how dogma developed, from what it developed, and how it is preserved and handed on.